state_management/java/http/order-processor/src/main/java/com/service/OrderProcessingServiceApplication.java
package com.service;

import com.fasterxml.jackson.databind.ObjectMapper;
import lombok.AllArgsConstructor;
import lombok.Getter;

import java.io.IOException;
import java.net.URI;
import java.net.URISyntaxException;
import java.net.http.HttpClient;
import java.net.http.HttpRequest;
import java.net.http.HttpResponse;
import java.time.Duration;
import java.util.concurrent.TimeUnit;

public class OrderProcessingServiceApplication {
    private static final String DAPR_STATE_STORE = "statestore";
    private static String DAPR_HOST = System.getenv().getOrDefault("DAPR_HOST", "http://localhost");
    private static String DAPR_HTTP_PORT = System.getenv().getOrDefault("DAPR_HTTP_PORT", "3500");
    private static final HttpClient httpClient = HttpClient.newBuilder()
            .version(HttpClient.Version.HTTP_2)
            .connectTimeout(Duration.ofSeconds(10))
            .build();

    public static void main(String[] args) throws IOException, URISyntaxException, InterruptedException {
        URI baseUrl = new URI(DAPR_HOST+":"+DAPR_HTTP_PORT);
        URI stateStoreUrl = new URI(baseUrl + "/v1.0/state/"+DAPR_STATE_STORE);
        for (int i = 1; i <= 10; i++) {
            int orderId = i;
            Order order = new Order(orderId);
            State state = new State(String.valueOf(orderId), order);
            State[] payload = new State[] {state};
            ObjectMapper objectMapper = new ObjectMapper();

            // Save state into a state store
            HttpRequest request = HttpRequest.newBuilder()
                    .POST(HttpRequest.BodyPublishers.ofString(objectMapper.writeValueAsString(payload)))
                    .uri(stateStoreUrl)
                    .build();
            HttpResponse<String> response = httpClient.send(request, HttpResponse.BodyHandlers.ofString());
            System.out.println("Saving order: "+ order.getOrderId());

            // Get state from a state store
            URI getStateURL = new URI(baseUrl + "/v1.0/state/"+DAPR_STATE_STORE+"/"+String.valueOf(orderId));
            request = HttpRequest.newBuilder()
                    .GET()
                    .uri(getStateURL)
                    .build();

            response = httpClient.send(request, HttpResponse.BodyHandlers.ofString());
            System.out.println("Order saved: "+ response.body());

            // Delete state from the state store
            URI deleteStateURI = new URI(baseUrl + "/v1.0/state/" + DAPR_STATE_STORE + "/" + String.valueOf(orderId));
            request = HttpRequest.newBuilder()
                    .DELETE()
                    .uri(deleteStateURI)
                    .build();
            response = httpClient.send(request, HttpResponse.BodyHandlers.ofString());
            System.out.println("Deleting order: "+ order.getOrderId());
            System.out.println("Deletion Status code :"+ response.statusCode());
            TimeUnit.MILLISECONDS.sleep(1000);
        }
    }
}

@AllArgsConstructor
@Getter
class Order {
    private int orderId;
}

@AllArgsConstructor
@Getter
class State {
    private String key;
    private Order value;
}
